linux-kernel - Re: [PATCH v2] tpm: fix an invalid condition in tpm_common

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190321135939.GF4603@linux.intel.com>
Date:   Thu, 21 Mar 2019 15:59:39 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     Tadeusz Struk <tadeusz.struk@...el.com>
Cc:     grawity@...il.com, James.Bottomley@...senPartnership.com,
        linux-integrity@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] tpm: fix an invalid condition in tpm_common_poll

On Tue, Mar 19, 2019 at 01:31:34PM -0700, Tadeusz Struk wrote:
> The poll condition should only check response_length,
> because reads should only be issued if there is data to read.
> The response_read flag only prevents double writes.
> The problem was that the write set the response_read to false,
> enqued a tpm job, and returned. Then application called poll
> which checked the response_read flag and returned EPOLLIN.
> Then the application called read, but got nothing.
> After all that the async_work kicked in.
> Added also mutex_lock around the poll check to prevent
> other possible race conditions.
> 
> Fixes: 9488585b21bef0df12 ("tpm: add support for partial reads")
> Reported-by: Mantas Mikulėnas <grawity@...il.com>
> Signed-off-by: Tadeusz Struk <tadeusz.struk@...el.com>

Can you send v3 with the comment and cc to stable? Then this
should be fine.

/Jarkko